FIG. 1 is a cross-sectional view of a cooling unit for a nuclear reactor control rod driving apparatus according to the related art. FIG. 2 is a cross-sectional view of the cooling unit of FIG. 1, taken along the line II-II.
As illustrated in FIGS. 1 and 2, the cooling unit according to the related art is arranged to cool the nuclear reactor control rod driving apparatus. Here, the nuclear reactor control rod driving apparatus includes a coil assembly 100 for generating the electromagnetic force for driving a control rod, and the coil assembly 100 includes coils 101 and housings 102 for enclosing the coils 101.
The coil 101 configured in the nuclear reactor control rod driving apparatus may thermally deteriorate by the electrical resistance heat due to the operating current, and thus it is necessary to reduce the possibility of thermal aging to increase the lifetime of the coil 101 by removing the heat.
In order to drive the control rod based on necessity, it is essential to include a cooling unit. However, a cooling unit for the nuclear reactor control rod driving apparatus according to the related art is designed in such a manner that heat generated in the coil 101 is simply cooled by the cooling air flow, whose path 130 is formed between the housing 102 and a cooling shroud-shell 120. For example, in case of an air cooling process, the external air removes the heat of the coil 101 by passing the cooling air flow path 130, but the cooling efficiency is significantly low.